Glass sheet bending apparatus

ABSTRACT

Glass sheet bending apparatus (20) including at least one deformable mold (22) has a linkage (26) that extends between mold members (24) and includes connector links (28) fixed to the mold members and having pivotal connections (32) to each other about axes that extend parallel to the glass sheet throughout the bending, and the linkage also has control links (34) that have pivotal connections (36) about axes that extend perpendicular to the glass sheet throughout the bending as well as having universal connections (38) to each other such that the linkage moves the mold members for bending with a constant radius of curvature. The bending apparatus (20) preferably has a pair of the deformable molds (22,44) that are arranged in lower and upper locations and have respective linkages (26,48) as well as having the mold members (24,46) thereof provided with quench openings (66) through which quenching gas is supplied to quench the bent glass sheet for heat strengthening or tempering. An actuating mechanism (154) of the apparatus is constructed so as to move the linkages (26,48) to perform the bending which may be performed by moving the deformable molds (22,44) toward each other during the bending.

This is a divisional of application Ser. No. 08/551,909, now U.S. Pat.No. 5,556,444, filed on Oct. 23, 1995 of Pauli T. Reunamaki entitled"Glass Sheet Bending Apparatus And Method" which is a divisional of Ser.No. 08/138,739 filed Oct. 18, 1993 of Pauli T. Reunamaki, entitled"Glass Sheet Bending Apparatus", now U.S. Pat. No. 5,498,275.

TECHNICAL FIELD

This invention relates to apparatus for bending glass sheets to aconstant radius of curvature and also relates to a method for bendingglass sheets.

BACKGROUND ART

As disclosed by U.S. Pat. No. 4,822,398 McMaster et al, glass sheetshave previously been bent between a pair of opposed bending platenswhose movement between flat and bent shapes during cyclical operation isprovided by a plurality of actuators connected to the platens. Theplatens are arranged in lower and upper positions with both platensprovided with wheels that engage the glass sheet during the bendingwhile the glass sheet is continually conveyed back and forth in order toreduce marking and distortion. After the bending, quench tubes that arepart of the platens supply quenching gas that provides tempering or heatstrengthening of the bent glass sheet.

U.S. Pat. No. 4,881,962 Reunamaki et al discloses bending and temperingof glass sheets wherein a roller conveyor is moved from a flat shape toa curved shape having an axis of curvature transverse to the directionof conveyance to provide bending of a glass sheet being conveyed therebyunder the actuation of cylinders. A linkage that connects the cylindershas all of its links pivotable about the axes transverse to thedirection of the conveyance. As such, the bending is controlled by theextent to which the cylinders are extended and retracted during eachcycle of operation.

DISCLOSURE OF INVENTION

An object of the present invention is to provide improved glass sheetbending apparatus for bending a glass sheet to a constant radius ofcurvature. In carrying out this object, the glass sheet bendingapparatus of the invention has particular utility for also quenching theglass sheet after it is bent to the constant radius of curvature.

The glass sheet bending apparatus of the invention includes a deformablemold for engaging a heated glass sheet to be bent. This deformable moldincludes a plurality of mold members that are movable with respect toeach other to bend the glass sheet. A linkage of the apparatus extendsbetween the mold members to control movement thereof with respect toeach other. The linkage includes connector links that are fixedlyconnected to the mold members and that have pivotal connections to eachother about axes that extend parallel to the glass sheet throughout thebending of the glass sheet. The linkage also includes control links thathave respective pivotal connections to the connector links about axesthat extend perpendicular to the glass sheet throughout the bending ofthe glass sheet. These control links have universal connections to eachother such that the linkage moves the mold members of the deformablemold to bend the glass sheet with a constant radius of curvature.

In its preferred construction, the glass sheet bending apparatus is ahorizontal conveyor having rotatable conveying elements supported by themold members to support and convey the glass sheet for horizontalmovement during the bending.

In its preferred construction, the glass sheet bending apparatus alsoincludes another deformable mold that cooperates with the firstdeformable mold in an opposed relationship and has a plurality of moldmembers that engage the glass sheet and are movable with respect to eachother to bend the glass sheet. This second deformable mold includes alinkage that extends between the mold members thereof to controlmovement thereof with respect to each other and has connector linksfixedly connected to the mold members and having pivotal connections toeach other about axes that extend parallel to the glass sheet during thebending. The second linkage has control links having pivotal connectionsto the connector links about axes that extend perpendicular to the glasssheet during the bending. The control links of the second mentionedlinkage have universal connections to each other such that the seconddeformable mold provides bending to the constant radius curved shape incooperation with the first mentioned deformable mold.

As disclosed, the deformable molds of the glass sheet bending apparatusare embodied by a lower deformable mold and an upper deformable moldthat oppose each other. The lower deformable mold is embodied by ahorizontal conveyor having rotatable conveying elements supported by themold members thereof to support and convey the glass sheet forhorizontal movement during the bending. The upper deformable mold islocated above the lower deformable mold that conveys the glass sheet inan opposed relationship. The upper deformable mold includes a pluralityof mold members having rotatable elements that engage the glass sheetand are movable with respect to each other to cooperate with the lowerdeformable mold to bend the glass sheet. The upper deformable mold likethe lower deformable molds includes an associated linkage that extendsbetween the mold members thereof to control movement thereof withrespect to each other and has connector links that are fixedly connectedto the mold members thereof and have pivotal connections to each otherabout axes that extend parallel to the glass sheet during the bending.The linkage of the upper deformable mold like the linkage of the lowerdeformable mold includes control links having pivotal connections to theconnector links about axes that extend perpendicular to the glass sheetduring the bending. The control links of the linkage of the upperdeformable mold like the linkage of the lower deformable mold haveuniversal connections to each other such that the upper deformable moldprovides bending to the constant radius curve shape in cooperation withthe lower deformable mold.

In the preferred construction of the glass sheet bending apparatus, eachconnector link has a pair of the control links pivotally mounted thereonin an X shape. This X shape of the pairs of the control links reducesthe loading applied to the pivotal connections between the connectorlinks. Furthermore, the universal connections of the control links toeach other are preferably embodied by spherical bearings. Thus, eachconnector link has a pair of the control links pivotally mounted thereonin an X shape with the control links connected to each other by thesespherical bearings in a manner that strengthens the linkageconstruction.

In the preferred construction disclosed, the glass sheet bendingapparatus has the mold members of the lower and upper deformable moldseach provided with an elongated shape with opposite ends. The linkagesof the lower and upper molds have connections to the respective moldmembers at adjacent ends of the mold members. Each of the lower andupper deformable molds also has another linkage of the same constructionas the first linkage thereof and having connections to the respectivemold members at the opposite adjacent ends thereof as the firstlinkages. Each elongated mold member is disclosed as being embodied by aquench tube having quench openings through which quenching gas issupplied to quench the glass sheet after the bending in order to provideheat strengthening or tempering. Each quench tube preferably includesquench plenums mounted thereon with rotatable elements of the respectivedeformable mold mounted between the quench plenums. These quench plenumsdefine the quench openings through which the quenching gas is suppliedto quench the bent glass sheet. Preferably, the quench plenums haveopposite ends that interfit with the quench plenums mounted on theadjacent quench tubes of the respective deformable mold and have quenchopenings positioned and oriented to provide a uniform distribution ofthe quenching gas that quenches the glass sheet.

An actuating mechanism of the glass sheet bending apparatus moves thelinkages of the lower and upper molds to perform the bending. Thisactuating mechanism has connections to the linkages to provide movementthereof which as disclosed is to upwardly concave shapes to move themold members of the lower and upper deformable molds and bend the glasssheet therebetween to an upwardly concave shape. The linkage of thelower deformable mold has a fixed center connection and also has movableend connections to the actuating mechanism, while the linkage of theupper deformable mold has a center support having a connection theretoand to the actuating mechanism and also has movable end connections tothe actuating mechanism. Flexible members of the actuating mechanism areconnected to the movable end connections of the linkages of the lowerand upper deformable molds. The actuating mechanism has wheels thatreceive the flexible members and also has an actuator that rotates thewheels to move the flexible members and linkages connected thereto inorder to move the lower and upper deformable molds to perform thebending.

The actuating mechanism of the glass sheet bending apparatus has aconstruction that permits adjustment of the spacing between the lowerand upper deformable molds as well as actuating the bending between theflat and bent shapes. This construction of the actuating mechanismincludes first and second rotary actuator members one of which is drivenby the rotary actuator. A second rotary actuator connects the first andsecond rotary actuator members and is operable to selectively prevent orprovide relative rotation between these rotary actuator members. Thewheels that receive the flexible members connected to the movable endconnections of the linkage of the lower deformable mold are fixed on oneof the rotary actuator members, while the wheels that receive theflexible members connected to the movable end connections of the linkageof the upper deformable member are fixed to the other rotary actuatormember. The center support for the linkage of the upper deformable moldhas a wheel assembly including a connection thereto and having a pair offlexible members wrapped in opposite directions about the wheelassembly. This center support for the linkage of the upper deformablemold also has a pair of wheels respectively mounted by the first andsecond rotary actuator members and respectively receiving the flexiblemembers of the wheel assembly in oppositely wrapped directions.Operation of the first rotary actuator moves the end connections of bothlinkages to perform the bending of the glass sheet between the lower andupper deformable molds, while operation of the second rotary actuatormoves both end connections and the center support connected to thelinkage of the upper deformable mold to provide movement that changesthe spacing between the lower and upper deformable molds. Operation ofboth actuators simultaneously performs the bending while also changingthe spacing between the opposed deformable molds.

Another object of the present invention is to provide an improved methodfor bending a heated glass sheet.

In carrying out the above method, a heated glass sheet is bent bylocating the heated glass sheet between a pair of opposed deformablemolds that are initially spaced from each other a greater thickness thanthe thickness of the glass sheet. The deformable molds aresimultaneously bent and moved toward each other such that both moldsengage the glass sheet to provide the bending of the glass sheet.

In performing the method for bending the heated glass sheet, it is alsopossible for the deformable molds after the bending to provide quenchinggas that quenches the bent glass sheet.

In the preferred practice of the method for bending the heated glasssheet, the heated glass sheet is initially supported and conveyed by oneof the deformable molds which is located below the other deformable moldin a lower and upper arrangement, and the deformable molds are bent toupwardly concave bent shapes as the molds are simultaneously movedtoward each other. Furthermore, the upper deformable mold is preferablymoved downwardly to provide the movement of the molds toward each other.

The objects, features and advantages of the present invention arereadily apparent from the following detailed description of the bestmode for carrying out the invention when taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side elevational view of glass sheet bending apparatusconstructed in accordance with the present invention;

FIG. 2 is an end elevational view taken through the apparatus along line2--2 in FIG. 1 and is illustrated with the deformable molds of theapparatus in a flat shape prior to the bending cycle;

FIG. 3 is an end elevational view similar to FIG. 2 but shown after thedeformable molds of the apparatus have been moved to a bent shape;

FIG. 4 is an end elevational view taken along the direction of line 4--4in FIG. 1 and illustrates linkages and an actuating mechanism thatcooperatively move the deformable molds between the flat shape and bentshapes of constant radius;

FIG. 5 is a side view taken along the direction of line 5--5 in FIG. 4to further illustrate the construction of the actuating mechanism andthe locations of the linkages that cooperatively move the lower andupper deformable molds between the flat shape and the bent shapes ofconstant radius;

FIG. 6 is an enlarged view taken in the same direction as FIG. 4 andillustrates the constructions of the linkages that control the movementof the deformable molds;

FIG. 7 is a further enlarged view taken partially in section toillustrate the construction of connector links and control links of eachlinkage;

FIG. 8 is a still further enlarged partial view of the linkageillustrating the manner in which the control links thereof are connectedto each other by universal connections that are preferably embodied byspherical bearings;

FIG. 9 is a top plan view of the upper linkage taken along the directionof line 9--9 in FIG. 6;

FIG. 10 is a bottom plan view of the lower linkage taken along thedirection of line 10--10 in FIG. 6;

FIG. 11 is a schematic view illustrating an actuating mechanism thatmoves the linkages to perform the bending;

FIG. 12 is a side elevational view taken along the direction of line12--12 in FIG. 2 to illustrate a drive mechanism that drives rotatableconveying elements of the lower deformable mold;

FIG. 13 is a longitudinal view taken along the direction of line 13--13in FIG. 1 to illustrate the manner in which the glass sheet ispositioned between the lower and upper deformable molds;

FIG. 14 is a side elevational view taken in the direction of line 14--14in FIG. 13 to further illustrate the manner in which the glass sheet issupported between the lower and upper deformable molds;

FIG. 15 is a bottom plan view taken along the direction of line 15--15in FIG. 14 to further illustrate quench plenums of the deformable molds;and

FIG. 16 is taken along the direction of line 16--16 in FIG. 14 throughthe upper deformable mold and illustrates the positioning of rotatableconveyor elements that engage the glass sheet during the bending.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to FIGS. 1-5 of the drawings, glass sheet bendingapparatus constructed in accordance with the present invention isgenerally indicated by 20 and is operable to perform the method of theinvention upon receiving a heated glass sheet to be bent from an unshownfurnace which may be of any conventional construction. The apparatus 20ultimately delivers the bent glass sheet to an unshown deliveryapparatus which may be of any suitable construction. As shown by thedrawings and hereinafter described, the bending by apparatus 20 startswith a heated flat glass sheet and is performed to provide a bent shapeof a constant radius. However, it should be appreciated that the bendingcan also be performed starting with a slightly prebent glass sheet suchas can be provided by prior conveyance on curved rolls of a rollerconveyor. Thus, in such cases, the bending will be performed startingwith curved mold shapes that are further bent rather than starting withthe flat mold shapes that are specifically illustrated.

With continuing reference to FIGS. 1-5, apparatus 20, includes adeformable mold 22 having a plurality of mold members 24 that aremovable with respect to each other to bend the glass sheet. A linkage 26illustrated in FIG. 4 extends between the mold members to controlmovement thereof with respect to each other. The linkage 26 includesconnector links 28 that are fixedly connected to the mold members 24 byconnections 30 illustrated in FIG. 14. Connector links 28 also havepivotal connections 32 through each other as shown in FIGS. 6, 7 and 10.These pivotal connections 32 have axes A that extend parallel to theglass sheet while flat as in FIG. 2 and throughout the bending thereofsuch as to the bent shape illustrated in FIG. 3. The linkage 26 alsoincludes control links 34 which, as illustrated in FIGS. 6, 7 and 10have respective pivotal connections 36 to the connector links 28 in aspaced relationship from the pivotal connections 32. The pivotalconnections 36 of the control links 34 to the connector links 28 areabout axes B (FIG. 7) that extend perpendicular to the glass sheet whileflat as illustrated in FIG. 2 and throughout the bending thereof such asto the bent shape shown in FIG. 3. These control links 34 as bestillustrated in FIGS. 7 and 8 have universal connections 38 to each othersuch that the linkage 26 moves the mold members 24 to bend the glasssheet with a constant radius of curvature. More specifically withreference to FIG. 7, the pivoting of the connector links 28 to which themold members are fixed is controlled about their associated pivotal axesA by the pivoting of the control links 34 about their associated pivotalconnection axes B to the connector links, and the universal connections34 permit this pivoting about axes B as well as about associated axes C(FIG. 7 and 8) parallel to axes A.

As best illustrated by FIGS. 13 and 14, the deformable mold 22 isembodied by a horizontal conveyor 40 having rotatable conveying elements42 supported by the mold members 24 to support and convey the glasssheet G for horizontal movement while flat and during the bending.

With further reference to FIGS. 1-5, the apparatus 20 also includes asecond deformable mold 44 that cooperates with the first deformable mold22 in an opposed relationship and has a plurality of mold members 46that engage the glass sheet and are movable with respect to each otherto bend the glass sheet. The second deformable mold 44 includes alinkage 48 that extends between the mold members 46 thereof to controlmovement thereof with respect to each other with substantially the sameconstruction as the previously described linkage 26. More specifically,the second linkage 48 includes connector links 28 fixedly connected suchas by connections 50 shown in FIG. 14 to the mold members 46 thereof andalso have pivotal connections 32 to each other about axes A that extendparallel to the glass sheet while flat and during the bending. Thesecond linkage 48 like the first linkage 26 also has control links 34having pivotal connections 36 to the connector links about axes B thatextend perpendicular to the glass sheet while flat as in FIG. 2 andduring bending such as to the bent shape shown in FIG. 3. The controllinks 34 of the second linkage 48 like the first linkage 26 haveuniversal connections 38 to each other. This construction of the secondlinkage 48 moves the mold members 46 of the second deformable mold 44 ingenerally the same manner as the first deformable mold and linkagedescribed above to provide bending to the constant radius curved shapein cooperation with the first deformable mold.

As previously described, the first deformable mold 22 is illustrated asbeing embodied by a horizontal conveyor 40 whose rotatable conveyingelements 42 are supported by the mold members 24 thereof to support andconvey the glass sheet for horizontal movement while flat and during thebending. The second deformable mold 44 is embodied as an upperdeformable mold located above the lower deformable mold that conveys theglass sheet in an opposed relationship. The upper deformable mold hasits mold members 46 provided with rotatable elements 52 that engage theglass sheet. Movement of the mold members 46 under the control oflinkage 48 in a generally similar manner to the previously describedfirst linkage 26 causes the bending of the glass sheet G to a constantradius curved shape in cooperation with the lower deformable mold.

As illustrated in FIGS. 9 and 10, each of the connector links 28preferably has a pair of the control links 34 pivotally mounted thereonin an X shape. Such a construction reduces the loading on the pivotalconnections 32 between the connector links to thereby provide a morerigid construction. Furthermore, as illustrated in FIGS. 7 and 8, theuniversal connections 38 between the control links 34 are illustrated asbeing constructed as spherical bearings 54. More specifically, eachcontrol link has a forked end 56 that mounts a pin 58 and also hasanother end 60 that is received by the forked end 56 of the adjacentcontrol link. Each pin 58 mounts the inner spherical bearing element 62with respect to the associated control link forked end 56, while eachcontrol link end 60 mounts the outer spherical bearing element 64. Theengaged spherical surfaces of the inner and outer elements 62 and 64thus provide the pivoting as previously described. Each connector link28 thus has a pair of the control links 34 mounted thereon in an X shapewith the control links connected to each other by these sphericalbearings 54. While other universal type connections could be utilized,the use of spherical bearings in association with the pair of controllinks 34 in the X shape provides accurate control of the linkagemovement with a relatively economical construction that can be readilyassembled.

As the lower and upper deformable molds 22 and 44 move from the flatshape of FIG. 2 to the constant radius bent shape of FIG. 3, the firstlinkage 26 that controls movement of the lower deformable mold islengthened while the second linkage 48 that controls movement of theupper deformable mold is shortened. As such, the first linkage 26 isconstructed as shown in FIG. 10 so that its control links 34 moveinwardly from the X shape to a more straightened shape as the bendingproceeds and move outwardly from the more straightened shape to the Xshape upon movement back to the flat shape in preparation for the nextcycle. On the other hand, the second linkage 48 that controls movementof the upper deformable mold has its control links 34 moved from a morestraightened configuration outwardly to a greater X shape as the bendingproceeds, and these control links 34 pivot inwardly to a lesser X shapeas the second deformable mold is moved back to the flat shape inpreparation for the next cycle.

As illustrated by FIGS. 1, 2 and 14, the mold members 24 and 46 of thelower and upper deformable molds 22 and 44 each have an elongated shapeincluding opposite ends 24a,24b and 46a,46b (FIG. 14). The linkages 26and 48 of the lower and upper deformable molds 22 and 44 have the fixedconnections 30 and 50 previously described to adjacent ends 24a and 46ato the respective mold members 24 and 46 at adjacent ends 24a and 46a.The lower and upper deformable molds 22 and 44 each have another linkage26 and 48 of the same construction as the previously discussed linkagesand having fixed connections 30 and 50 to the respective mold members 24and 46 at the opposite adjacent ends 24b and 46b as the other linkages.Each elongated mold member 24 and 46 is constructed as a quench tubehaving quench openings 66 (FIG. 15) through which quenching gas issupplied to quench the glass sheet after the bending such as for heatstrengthening or tempering. More specifically as illustrated in FIGS. 1,2 and 3, an elongated quench duct 68 is mounted on the factory floor 70and has a round cross-section from which flexible quench conduits 72extend along spaced locations to each of the elongated lower quenchtubes 24. Pressurized quench air is supplied through supply ducts 74 tothe lower quench duct 68 under the control of associated dampers 76 suchthat the pressurized quenching gas can be fed through the flexible ducts72 to the lower side of the bent glass sheet.

With continuing reference to FIGS. 1-3, a framework 78 of the bendingand quenching apparatus supports a pair of upper quench ducts 80 thathave elongated shapes with round cross-sections like the lower quenchduct 68 mounted on the factory floor as described above. Flexible quenchconduits 82 connect the upper quench ducts 80 at spaced locations alongthe length of the apparatus with each of the upper quench tubes 46 ofthe upper deformable mold 44. Supply ducts 84 controlled by associateddampers 86 supply quenching gas to the upper quench ducts 80 for flowthrough the flexible quench conduits 82 to the elongated upper quenchtubes 46 and eventual flow through the quench openings thereof to quenchthe upper surface of the bent glass sheet in cooperation with thequenching gas supplied to the lower surface thereof by the quench tubes24 of the lower deformable mold as described above.

As illustrated in FIGS. 14 and 15, each quench tube 24 and 46 includesquench plenums 88 mounted thereon with the rotatable elements 42 and 52of the respective deformable molds 22 and 44 mounted on the quench tubesbetween the quench plenums. Each quench plenum 88 has a two-piece castaluminum construction which is secured by connectors 90 such that around inlet 92 (FIG. 15) of each quench plenum supplies the quenchinggas from the associated quench tube to its quench openings 66. Quenchplenums 88 also have ends 94 that interfit with the quench openings 66positioned and oriented to provide a uniform distribution of thequenching gas that quenches the glass sheet after the bending.

With reference to FIG. 13, the lower deformable mold 22 includes aplurality of deformable drive shafts 96 positioned along its length.These deformable drive shafts 96 support the rotatable conveyor elements42 of the lower deformable mold 22 and may be constructed of a suitableplastic with a cross-section that provides driving engagement withopenings through the conveyor elements 42. Opposite ends of each driveshaft 96 are received by drive journals 98 mounted on a pair oflaterally spaced mold mounting members 100 respectively located on theopposite lateral sides of the lower deformable mold. As illustrated bycombined reference to FIGS. 4 and 12, each mounting member 100 of thelower deformable mold has a drive mechanism 102 mounted thereon to drivethe adjacent ends 104 (FIG. 13) of the deformable drive shafts 96. Thisdriving is performed by an electric motor 106 whose output 108 drives acontinuous chain 110 that is received by idler sprockets 112, a tensionadjuster socket 114 and drive sprockets 116 connected to the ends 104 ofthe deformable drive shafts. This driving of the drive shafts 96 isperformed as the flat glass sheet is received between the lower andupper deformable molds 22 and 44 as illustrated in FIG. 2 and whilebeing bent to the bent shape of a constant radius such as illustrated inFIG. 3 as well as after the bending during the quenching to provide heatstrengthening or tempering as previously described.

It should be noted that the deformable drive shafts 96 as illustrated inFIG. 13 have L-shaped journals 118 whose orientation is preferablyswitched along the direction of conveyance from one drive shaft to thenext so that the conveyor elements 42 engage the glass sheet atdifferent locations in order to prevent strip marking of the glass sheetbeing bent. These journals 118 are supported by mounts 120 on the lowerquench tubes 24 and receive the deformable drive shaft between adjacentconveyor elements 42 with tubular spacers spacing the conveyor elementsfrom each other and from the journals 118. More specifically, thecentral drive shaft extends through the tubular spacers as well asthrough the drive openings of the conveyor elements 42 as previouslydescribed to provide the driving with the spacers locating the conveyorelements with respect to each other and with respect to the journals118. Furthermore, it should be noted that each conveyor element 42 aswell as the rotatable elements 52 of the upper deformable mold has anouter annular strip of an aromatic polyamide fiber such as Kevlar thatengages the glass sheet.

With combined reference to FIGS. 13, 15 and 16, the rotatable elements52 of the upper deformable mold are each rotatably mounted by anunsymmetrical journal 122 that is secured to the associated upper quenchtube 46 by fasteners 124 with alternate positioning along the directionof conveyance from one rotatable element to the next so that, as withthe conveyor elements 42 of the lower deformable mold, there is no stripmarking of the heated glass sheet due to engagement only at onelocation.

The lower and upper linkages 26 and 48 illustrated in FIG. 6 aspreviously described each has connector links 28 whose construction isbest illustrated in FIG. 7. More specifically, each connector link 28has a connector link member 126 which, as illustrated in FIGS. 9 and 10,has a forked end 128 and another end 130 that is received by the forkedends of the adjacent link member 126 in an interfitted relationship thatis secured by a pivot pin 132 of the associated pivotal connection 32.Each connector link 26 also has a link tube 134 that is secured by welds136 to the link tube 126 with an interfitted engagement 138 thatrigidifies the connection. A link shaft 140 of each connector link 28 isreceived within the link tube 134 and has one end secured to the linkmember 126 by an axial connector 142 embodied by a threaded bolt.Adjacent the other end of the link tube 134, threaded adjusters 144which are spaced at 90° intervals locate the link shaft 144 along axis Bof the connector link.

With continuing reference to FIG. 7, the control links 34 are mounted onthe end of the link shaft 140 opposite the connector 142 and are securedby a threaded lock nut 146 with a bushing 148 spacing the control linksfrom each other. More specifically, each control link 34 has a pair ofantifriction bearings 150 whose inner races are mounted by a reduceddiameter link shaft portion 152 and whose outer races are secured to thecontrol shaft so that the bearing elements between the races by rollingcontact support the control links for their pivoting. More specifically,the spaced relationship of the control links 34 from the pivotalconnections 32 of the adjacent connector links 28 and the parallelrelationship of the axes A of pivotal connections 32 with respect to theglass sheet as well as the perpendicular relationship of the axes B ofcontrol link pivoting provides the constant radius of curvature of thebent glass sheet as previously described. In this connection, it shouldbe noted that the extent to which the control links 34 straighten fromtheir angular relationship shown should be limited to about 10°-15° froma straight line so that binding does not take place upon attemptedreverse movement toward the more angular location as previouslydescribed in connection with FIGS. 9 and 10.

With reference to FIGS. 4 and 5, the glass sheet bending apparatus 20includes an actuating mechanism 154 that is mounted on the framework 78and operable to move the lower and upper linkages 26 and 48 so that thedeformable platens move between the flat shape of FIG. 2 and a constantradius bent shape as illustrated in FIG. 3 to perform the bending. Morespecifically, the actuating mechanism 154 has connections 156, 158 and160 to the lower and upper linkages 26 and 48 to provide movementthereof to the upwardly concaved shapes such as illustrated in FIG. 3 tomove the mold members 24 and 46, i.e. quench tubes, and bend the glasssheet therebetween to an upwardly concave shape of a constant radius aspreviously described. As shown in FIG. 4, the lower linkage 26 has afixed center connection 162 to the framework 78. This fixed centerconnector is provided by a suitable link extender 164 (FIG. 6) from theconnector link tube 134 of the central connector link 28, with thisextender having portions located on opposite sides of the associatedcontrol links 34 so as not to interrupt their pivoting as previouslydescribed. Each end of the lower linkage 26 as shown in FIG. 4 also hasan associated movable end connection 156 to the actuating mechanism 154.Furthermore, the upper linkage 48 of the upper deformable mold has acenter support 166 which includes the connection 160 to the center ofthe upper linkage 48. More specifically, this center connection 160 isprovided as shown in FIG. 6 to the central connector link 28 by a linkextender 168 that extends around the associated control links 34 so asnot to prevent their pivoting as previously described. The upper linkage48 of the upper deformable mold also has movable end connections 158 tothe actuating mechanism 154 as shown in FIG. 4.

As illustrated in both FIGS. 4 and 5, the actuating mechanism 154includes flexible members 170 and 172 connected to the movable endconnections 156 and 158, respectively, of the lower and upper linkages26 and 48 of the lower and upper deformable molds. These flexiblemembers are preferably embodied by chains. The actuating mechanism 154has wheels 174 and 176 that are preferably embodied by sprockets andrespectively receive the flexible members 170 and 172 embodied by thechains connected to the movable end connections 156 and 158 of the lowerand upper linkages as previously described. A first actuator 178, whichis an electric motor, rotates the wheels in opposite directions as ishereinafter described to wind and unwind the flexible members 170 and172 on their associated wheels 174 and 176 in order to move thedeformable molds between the flat and bent shapes. Of course, a greaterextent of rotation provides a greater amount of winding and hencebending to a greater extent from the flat shape to a shorter radius ofconstant curvature.

As illustrated in FIG. 11, the actuating mechanism 154 includes firstand second rotary actuator members 180 and 182 one of which is driven bythe first actuator 78, specifically the actuator member 180. A secondrotary actuator 184 of the actuating mechanism connects the first andsecond rotary actuator members 180 and 182 and is operable toselectively prevent or provide relative rotation between these actuatormembers. More specifically, this second rotary actuator 184 like thefirst one is an electric motor and is mounted on the rotary actuatormember 182 with its rotary output rotatively connected such as bybelting, gearing or chain driving to the other rotary actuator member180.

With continuing reference to FIG. 11, the wheels 174 that receive theflexible members 170 connected to the movable end connections of thelinkage of the lower deformable mold are fixed on one of the rotaryactuator members, which specifically is the one rotary actuator member180 that is driven by the actuator 178 as previously described. Thewheels 176 that receive the flexible members 172 connected to themovable end connections of the linkage of the upper deformable mold arefixed to the other rotary actuator member, which is the rotary actuatormember 182 as shown. More specifically, these rotary actuator members180 and 182 are respectively illustrated as a central shaft and a tubethat receives the shaft such that the second rotary actuator 184provides a connection between the shaft and the tube and is operable toprovide the relative rotation therebetween as previously described. Itshould also be noted as illustrated in FIGS. 4 and 5 that the flexiblemembers 170 and 172 extend over associated idler wheels 185 which arepreferably embodied by sprockets rotatably mounted on the framework 78so that the centrally mounted actuating mechanism 154 can be connectedvertically to both ends of both of the linkages 26 and 48 by makingangular bends as needed. Furthermore, the linkages 26 and 48 at bothends of each deformable mold 22 and 44 have respective flexible members170 and 172 as well as associated wheels 174 and 176 so that the linkageat each end of each deformable mold is bent in the same manner as thelinkage at the other end. Likewise, there is a center support 166supporting the center of each upper linkage 48 as is hereinafter morefully described.

As illustrated in FIG. 11, each center support 166 for the upper linkage48 of the upper deformable mold has a wheel assembly 186 and as shown inFIG. 4 has the previously mentioned connection 160 to the center of theupper linkage 48 that controls the bending of the upper deformable mold.More specifically, the center support 166 includes a journal 188 throughwhich a shaft 190 extends and has a pair of wheels 192 preferablyembodied by sprockets mounted on its opposite ends, and a support member194 depends downwardly from the journal 188 to the connection 160 shownin FIG. 4 to the center of the upper linkage as previously described.The center support 166 as best shown in FIG. 11 also has a pair offlexible members 196 preferably embodied by chains wrapped in oppositedirections about the wheel assembly 186. The center support 166 alsoincludes a pair of wheels 198 and 200 preferably embodied by sprocketsrespectively mounted by the first and second rotary actuator members 180and 182 which, as previously mentioned, are the shaft and the tubethrough which the shaft extends. These wheels 198 and 200 respectivelyreceive the flexible members 196 in oppositely wrapped directions toeach other.

Operation of only the first actuator 178 as previously described movesthe end connections 156 and 158 (FIG. 4) of both linkages to perform thebending of the glass sheet between the lower and upper deformable moldswhile the center support 166 maintains the center connection 160 of theupper linkage 48 stationary. This stationary support results from thefact that while one wheel 198 or 200 unwinds the associated flexiblemember 196 as shown in FIG. 11 during operation of the first actuator178, the other wheel 198 or 200 will then wind the associated flexiblemember such that even though the wheels 192 may rotate, the shaft 190remains in the same vertical position such that the support member 194depending from its journal 188 to the upper linkage center connection160 shown in FIG. 4 does not move. However, operation of the secondrotary actuator 184 provides relative rotation between the first andsecond rotary actuator members 180 and 182 which moves the endconnections 158 and the center connection 160 of the upper linkage 48shown in FIG. 4 vertically to provide a change in the spacing betweenthe lower and upper deformable molds. More specifically, the adjustmentof the end connections takes place due to relative rotation between therotary members 180 and 182 such that the flexible members 172 adjust theend connections. Furthermore, while the one wheel 198 of the centersupport 166 remains stationary on the first actuator member 180, theother wheel 200 of the center support 166 is rotated with the net effectbeing a rotation of the wheel assembly 186 and an effective winding orunwinding that changes the vertical position of the shaft 190 and itsjournal 188 from which the support member 194 depends to the centerconnection 160 (FIG. 4) of the upper linkage 48.

It should also be noted that during a bending cycle it is possible tooperate both actuators 178 and 184 at the same time. This concurrentoperation of actuators 178 and 184 allows a greater spacing between thelower and upper deformable molds 22 and 44 while in the flat shape tofacilitate movement of the glass sheet between the molds. Thereafter,the concurrent operation of the actuators moves the upper deformablemold 44 downwardly toward the lower deformable mold 22 as the bending isperformed. Of course, the second actuator 184 should terminate operationafter the upper deformable mold 44 has moved downwardly toward the lowerdeformable mold 22 into a spaced relationship approximately equal to theglass sheet thickness. During movement back to the flat shape inpreparation for the next cycle, operation of both actuators 178 and 184moves the upper deformable mold 44 upwardly away from the lowerdeformable mold 22 into the farther spaced relationship from which thebending begins. This operation allows the opposed deformable molds 22and 44 to be initially spaced from each other a greater thickness thanthe thickness of the glass sheet and to thereafter simultaneously bendthe deformable molds and move the molds toward each other such that bothmolds engage the glass sheet to provide its bending. The deformablemolds may then provide the quenching gas as previously described toquench the bent glass sheet. Furthermore, the deformable mold 22 islocated below the deformable mold 44 in a lower and upper arrangementwith the lower deformable mold 22 functioning as a conveyor aspreviously described, and the molds are bent to upwardly concave shapesas they are simultaneously moved toward each other with the upperdeformable mold 44 being moved downwardly to provide the movement of themolds toward each other. Also, it should be appreciated that this moldmovement toward each other at the ends of the linkages is a relativemovement in that the upper linkage ends move upwardly slower than thelower linkage ends as the bending is performed with both rotaryactuators 178 and 184 operating the actuating mechanism as describedabove.

As previously mentioned, it is possible for the lower and upperdeformable molds 22 and 44 to receive a prebent glass sheet rather thana flat glass sheet such that the bending proceeds from a partially bentshape to a further bent shape, after which quenching can be performed aspreviously described.

While the best mode for carrying out the invention has been described indetail, those familiar with the art to which this invention relates willrecognize various alternative designs and embodiments for practicing theinvention as defined by the following claims.

What is claimed is:
 1. Glass sheet bending apparatus comprising: lowerand upper deformable molds that oppose each other and receive a heatedglass sheet to be bent; each deformable mold including a plurality ofmold members that are engageable with the glass sheet and are movablewith respect to each other to bend the glass sheet; lower and upperlinkages that respectively extend between the mold members of the lowerand upper deformable molds to control movement thereof with respect toeach other; an actuating mechanism that moves the linkages of the lowerand upper deformable molds to bend the glass sheet; the linkage of thelower deformable mold having a fixed center connection and also havingmovable end connections; the linkage of the upper deformable mold havinga center support and also having movable end connections; the actuatingmechanism including flexible members connected to the movable endconnections of the linkages of the lower and upper deformable molds; theactuating mechanism having wheels that receive the flexible members; theactuating mechanism including first and second rotary actuator members;a first actuator that rotatively drives the first rotary actuatormember; a second rotary actuator that connects the first and secondrotary actuator members and is operable to selectively prevent orprovide relative rotation therebetween; the wheels that receive theflexible members connected to the movable end connections of the linkageof the lower deformable mold being fixed on one of the rotary actuatormembers; the wheels that receive the flexible members connected to themovable end connections of the linkage of the upper deformable memberbeing fixed to the other rotary actuator member; the center support forthe linkage of the upper deformable mold having a wheel assemblyincluding a connection thereto and having a pair of flexible memberswrapped in opposite directions about the wheel assembly; and the centersupport for the linkage of the upper deformable mold also having a pairof wheels respectively mounted by the first and second rotary actuatormembers and respectively receiving the flexible members of the wheelassembly in oppositely wrapped directions such that operation of thefirst actuator rotates the wheels to move the flexible members and tomove the end connections of both linkages to perform the bending of theglass sheet between the lower and upper deformable molds, whileoperation of the second actuator rotates the wheels to move the flexiblemembers to move both end connections and the center support connectionof the linkage of the upper deformable mold to provide movement thatchanges the spacing between the lower and upper deformable molds. 2.Glass sheet bending apparatus as in claim 1 further comprising: theflexible members being chains and the wheels being sprockets thatreceive the chains.
 3. Glass sheet bending apparatus as in claim 1further comprising: the first and second actuators being electricmotors.
 4. Glass sheet bending apparatus as in claim 1 furthercomprising: one of the rotary actuator members being a shaft, the otherrotary actuator member being a tube that receives the shaft, and thesecond rotary actuator selectively providing a connection between theshaft and the tube or permitting relative rotation therebetween. 5.Glass sheet bending apparatus as in claim 1 further including aframework, and also including idler wheels that are mounted on theframework and that receive the flexible members connected to the movableend connections of the linkages of the lower and upper deformable molds.6. Glass sheet bending apparatus as in claim 1 further comprising: themold members of the lower and upper deformable molds each having anelongated shape and being quench tubes having quench openings throughwhich quenching gas is supplied to quench the glass sheet after thebending.
 7. Glass sheet bending apparatus as in claim 6 wherein eachquench tube includes quench plenums mounted thereon, each deformablemold having rotatable elements mounted between the quench plenums, andthe quench plenums defining the quench openings through which thequenching gas is supplied to quench the bent glass sheet.
 8. Glass sheetbending apparatus as in claim 7 wherein the quench plenums have oppositeends that interfit with the quench plenums mounted on the adjacentquench tubes of the respective deformable mold and having quenchopenings positioned and oriented to provide a uniform distribution ofthe quenching gas that quenches the glass sheet.
 9. Glass sheet bendingapparatus comprising: lower and upper deformable molds that oppose eachother and receive a heated glass sheet to be bent; each deformable moldincluding a plurality of mold members that are engageable with the glasssheet and are movable with respect to each other to bend the glasssheet; lower and upper linkages that respectively extend between themold members of the lower and upper deformable molds to control movementthereof with respect to each other; an actuating mechanism that movesthe linkages of the lower and upper deformable molds to bend the glasssheet; the linkage of the lower deformable mold having a fixed centerconnection and also having movable end connections; the linkage of theupper deformable mold having a center support and also having movableend connections; the actuating mechanism including chains connected tothe movable end connections of the linkages of the lower and upperdeformable molds; the actuating mechanism having sprockets that receivethe chains; the actuating mechanism including first and second rotaryactuator members one of which is a shaft and the other of which is atube that receives the shaft; a first electric motor actuator thatrotatively drives the first rotary actuator member; a second electricrotary actuator that connects the first and second rotary actuatormembers and is operable to selectively prevent or provide relativerotation therebetween; the sprockets that receive the chains connectedto the movable end connections of the linkage of the lower deformablemold being fixed on one of the rotary actuator members; the sprocketsthat receive the chains connected to the movable end connections of thelinkage of the upper deformable member being fixed to the other rotaryactuator member; the center support for the linkage of the upperdeformable mold having a wheel assembly including a connection theretoand including sprockets and a pair of chains wrapped in oppositedirections about its sprockets; and the center support for the linkageof the upper deformable mold also having a pair of sprocketsrespectively mounted by the first and second rotary actuator members andrespectively receiving the chains of the wheel assembly in oppositelywrapped directions such that operation of the first actuator rotates thesprockets to move the chains and to move the end connections of bothlinkages to perform the bending of the glass sheet between the lower andupper deformable molds, while operation of the second actuator rotatesthe sprockets to move the chains to move both end connections and thecenter support connection of the linkage of the upper deformable mold toprovide movement that changes the spacing between the lower and upperdeformable molds.
 10. Glass sheet bending apparatus comprising: lowerand upper deformable molds that oppose each other and receive a heatedglass sheet to be bent; each deformable mold including a plurality ofmold members that have elongated shapes embodying quench tubes; eachquench tube including quench plenums mounted thereon and having quenchopenings; each deformable mold including rotatable elements mounted onthe quench tubes between the quench plenums; the rotatable elementsbeing engageable with the glass sheet and the mold members being movablewith respect to each other to bend the glass sheet; lower and upperlinkages that respectively extend between the mold members of the lowerand upper deformable molds to control movement thereof with respect toeach other; an actuating mechanism that moves the linkages of the lowerand upper deformable molds to bend the glass sheet; the linkage of thelower deformable mold having a fixed center connection and also hasmovable end connections; the linkage of the upper deformable mold havinga center support and also having movable end connections; the actuatingmechanism including chains connected to the movable end connections ofthe linkages of the lower and upper deformable molds; the actuatingmechanism having sprockets that receive the chains; the actuatingmechanism including first and second rotary actuator members one ofwhich is a shaft and the other of which is a tube that receives theshaft; a first electric motor actuator that rotatively drives the firstrotary actuator member; a second electric rotary actuator that connectsthe first and second rotary actuator members and is operable toselectively prevent or provide relative rotation therebetween; thesprockets that receive the chains connected to the movable endconnections of the linkage of the lower deformable mold being fixed onone of the rotary actuator members; the sprockets that receive thechains connected to the movable end connections of the linkage of theupper deformable member being fixed to the other rotary actuator member;the center support for the linkage of the upper deformable mold having awheel assembly including a connection thereto and including sprocketsand a pair of chains wrapped in opposite directions about its sprockets;and the center support for the linkage of the upper deformable mold alsohaving a pair of sprockets respectively mounted by the first and secondrotary actuator members and respectively receiving the chains of thewheel assembly in oppositely wrapped directions such that operation ofthe first actuator rotates the sprockets to move the chains and to movethe end connections of both linkages to perform the bending of the glasssheet between the lower and upper deformable molds, while operation ofthe second actuator rotates the sprockets to move the chains to moveboth end connections and the center support connection of the linkage ofthe upper deformable mold to provide movement that changes the spacingbetween the lower and upper deformable molds.